Of the Protein metabolism is a vital process in the human body. It is responsible for the uptake, build-up, breakdown and removal of proteins. Proteins are the building blocks of human cells. If the metabolism does not run smoothly, there is a so-called metabolic disorder. The most common disorder in protein metabolism in newborns is phenylketonuria.
The protein metabolism in the human body controls the uptake, build-up, breakdown and excretion of proteins. Proteins, also called proteins, are made up of amino acids, e.g. Lysine.
The protein metabolism in the human body controls the uptake, build-up, breakdown and excretion of proteins. Proteins, also known as proteins, are made up of amino acids. There are a total of 20 different amino acids. Eight of them are essential. This means that they have to be taken in through food, as the organism cannot produce them itself.
Protein metabolism will too Protein- or Amino acid metabolism called. The body builds its cells, enzymes and hormones from proteins. Proteins can also serve as an energy supplier.
In addition to fats and carbohydrates, proteins are an important main nutrient group for the human body. The proteins are absorbed through food and broken down in the stomach by the enzyme pepsin into polypeptides and oligopeptides.
These substances are released into the small intestine in regular bursts. In this organ, the peptides are broken down into chymotrypsin by the enzyme trypsin. In this form the broken down nutrient is available. The proteins reach the small intestine as amino acids and are absorbed through its wall.
The remaining, unabsorbed amino acids are broken down in the body or used for the production of endogenous proteins, for example enzymes. For this it is important that all relevant amino acids are available in sufficient quantities. If only one amino acid is missing, the production of the building blocks that need this amino acid can no longer take place.
There are 20 amino acids. The organism can produce twelve of them itself. The remaining eight amino acids cannot be produced by the human body. These are essential and must be ingested through food. The organism needs proteins for growth and repair processes. Proteins are the building blocks of all human cells. Protein is needed to make new cells or repair damaged cells. As the protein stores in the body are limited, this nutrient must be absorbed through regular consumption of protein-rich foods.
Enzymes and hormones are also built from amino acids. Most of these proteins are built up in the liver. But also in all other cells there is a regular build-up of proteins from amino acids.
When there is a lack of nutrients, in addition to carbohydrates and fats, proteins can also be used to produce energy for the body. To do this, the proteins from the spleen, muscles and liver are converted into pyruvate. This substrate can be used directly as an energy source or indirectly converted to glucose through a further metabolic process. This process produces ammonia, which is toxic for the organism. A small part of it is excreted directly through the kidneys. The rest is converted to urea in the liver and released in the urine.
In order for the metabolism to run properly, it is necessary that the substances required are available and that different enzymes work together. If individual parts of the process are defective because a certain enzyme is not available, the metabolism cannot function properly. An enzyme defect can therefore be the cause of a metabolic disease. The body then lacks certain enzymes, the substances are produced or stored in too large numbers. This can be due to genetic factors or an unhealthy lifestyle.
The most common metabolic disorder in infants in the protein metabolism is the so-called phenylketonuria. The cause of the disease is an enzyme defect, which means that the amino acid phenylalanine is not converted to tyrosine. Phenylalanine cannot be broken down in the body and accumulates in the brain of those affected. If left untreated, the patients suffer irreparable damage to the brain. Motor and mental development is impaired as a result. Furthermore, too little tyrosine is available. This amino acid is required for the formation of various hormones.
The only effective therapy is a diet with low-phenylalanine foods. A diet with low-protein foods such as meat, eggs, milk and cheese is particularly recommended up to the age of 12, as the brain develops completely during these years. However, it is advisable to avoid protein-rich foods for life with this disease. Because phenylketonuria is relatively common, every newborn is tested for the disorder.
Another disease in protein metabolism is so-called amyloidosis. In this disorder, so-called amyloid accumulates around body cells. Compared to other endogenous proteins, the amyloid has an abnormal structure. As a result, it cannot be broken down and attaches itself to one or more organs. Deposits on oranges can impair their functionality. All organs of the human body can be affected. Certain underlying diseases can promote the occurrence of this disorder. In this case, the underlying disease must be treated.
Amyloidoses that do not cause symptoms are also possible. Usually these do not need to be treated. On the other hand, amyloidoses in organ-related disease symptoms, such as heart failure due to deposits on the heart muscle, require symptomatic treatment. The cause of the amyloidase is still largely unclear.